How to debug Node.JS child process in Visual Studio code?

Question

How to debug Node.JS child process in VS Code?
Here is an example of the code I'm trying to debug:

var spawn = require('child_process').spawn;
var scriptPath = './child-script.js';
var runner_ = spawn('node', [scriptPath]);

Answer 1

You can easily add a new launch configuration to launch.json, which allows you to connect to a running instance of node with a specific port:

{
        "name": "Attach to Node",
        "type": "node",
        "address": "localhost",
        "port": 5870,
}

Just make sure fork / create a node process with the argument --debug or -debug-brk.

Answer 2

In your launch configuration add "autoAttachChildProcesses": trueas below

{
  "type": "node",
  "request": "launch",
  "name": "Launch Program",
  "autoAttachChildProcesses": true,
  "program": "${workspaceFolder}/index.js"
}

Answer 3

npm child-process-debug.

vscode:

-,

   {
        "name": "Attach",
        "type": "node",
        "request": "attach",
        "port": 5858,
        "address": "localhost",
        "restart": false,
        "sourceMaps": false,
        "outFiles": [],
        "localRoot": "${workspaceRoot}",
        "remoteRoot": null
    },
    {
        "name": "Attach child",
        "type": "node",
        "request": "attach",
        "port": 5859,
        "address": "localhost",
        "restart": false,
        "sourceMaps": false,
        "outFiles": [],
        "localRoot": "${workspaceRoot}",
        "remoteRoot": null
    }

:

• node --debug $ node --debug master.js
• Join the master.jsnode process using Attachthe debug panel
• Breakpoint of a place in progress child.js
• Quickly disconnects from the process mainand joins the process childusingAttach child

For debugging Fro, you can delay message passing between processes with setTimeout

// master.js
var child = child_process.fork(__dirname + './child.js')
setTimeout(function() {
    child.send('...')
}, 5000)

Answer 4

Make it Changes in your Configuration, autoAttachChildProcess: true